1. Field of the Invention
In general, the present invention relates to impression trays and similar devices that are used to create dental models. More specifically, the present invention relates to dental modeling methods and devices that use light curable material within the mouth to create dental impressions.
2. Description of the Prior Art
When a patient is having dental work that requires teeth to be replaced, capped, covered with a bridge, or otherwise reformed with a prosthesis, it is the job of the dental practitioner to replace the involved teeth with a prosthesis that is both aesthetically pleasing and bio-mechanically correct. In the past, if a patient were to have teeth replaced or reformed, the dental practioner would produce a study model of the patient's teeth before the involved teeth were ground, removed or otherwise prepared. Similarly, the dental practioner would also model the patient's mouth after the involved teeth were prepared. Both models were then used to create a master cast from which the needed prosthesis could be formed. Due to the variables involved in preparing models using prior art methods, the initial master cast could be less than accurate. Prosthetics developed from the master cast therefore often did not properly fit and either the master cast or the prosthesis had to be repeatedly corrected. As a result, the fitting of a proper prosthesis often was obtained by trial and error, wherein the prosthetic had to be fitted and corrected numerous times before it became accurate.
One of the more common errors that occur in prior art dental modeling schemes is the inaccurate registration of the centric occlusion and vertical dimension of the involved teeth. Such inaccuracies are transferred to the prosthesis and create interdigitation misalignments in the mouth once the prosthesis is set into place. As such, the prosthesis must either be replaced or reformed to ensure a proper bite.
One of the contributing factors that leads to inaccurate models is that dentists do not always take accurate impressions. In the prior art, impressions are most commonly made using a plastic impression tray that is filled with an impression material. The impression tray is placed into the mouth and the patient bites into the impression material supported by the tray. However, impression trays only come in a few different sizes. The mouths of patients come in an infinite variety of shapes and sizes. Accordingly, available impression trays do not always properly fit in a patient mouth. The result is an incomplete or inaccurate impression that produces flawed models.
In an attempt to improve the accuracy of taking a dental impression, prior art systems have been developed where the impression material can be manipulated within the mouth by the dentist to ensure proper positioning. Once the impression material is properly positioned, the material is cured in place within the mouth. Such prior art dental impression systems are exemplified by U.S. Pat. No. 5,616,027 to Jacobs, entitled Custom Dental Tray and U.S. Pat. No. 4,867,682 to Hammesfahr, entitled Dental Impression Tray.
A problem associated with such prior art dental impression systems is that the impression tray creates a barrier around the impression material that prevents a dentist from either viewing or manipulating a large percentage of the impression material. Accordingly, if the impression material were not to properly form around a tooth in a specific area under the impression plate, the dentist would not be able to notice or correct the defect until the impression material were cured and removed. Depending upon the degree of the defect, the impression would then have to be corrected or retaken.
A need therefore exists in the art for an dental impression system that does not obstruct a dentist's access to the impression material supported by that tray. In such a manner, a dentist can view how the impression material is covering the teeth before the impression material is cured and removed.
A need also exists in the art for a dental impression modeling method and apparatus that greatly reduces the complexity of accurately creating a proper dental impression.
These needs are met by the apparatus and method as described and claimed below.